Method and System of Assigning a Channel without Paging

ABSTRACT

A method and system for setting up a communication with a given mobile station served by a RAN that defines one or more coverage areas. The RAN may receive an indication of a location of the given mobile station. The RAN may then use the location of the given mobile station to identify one or more wireless coverage areas associated with the given mobile station. The RAN may also receive a request to set up a communication with the given mobile station. In response, the RAN may assign a channel for the communication to the given mobile station in each identified wireless coverage area without first paging the given mobile station.

REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. patent application Ser. No. 11/810,665,filed on Jun. 6, 2007, the entirety of which is hereby incorporated byreference.

FIELD OF THE INVENTION

The present invention relates to wireless communications and, moreparticularly, to setting up a wireless communication with a mobilestation served by a radio access network.

BACKGROUND

The art and popularity of wireless communications has grownsignificantly over recent years. Indeed, millions of people are engagingin voice and data communications using mobile stations such as cellulartelephones and Personal Digital Assistants (PDAs). In principle, a usercan communicate over the Internet or call anyone over the PublicSwitched Telephone Network (PSTN) from any place inside the coveragearea of a cellular wireless network.

In a typical cellular wireless network, an area is dividedgeographically into a number of cells and cell sectors, each defined bya radio frequency (RF) radiation pattern from a respective antennastructure in the cellular wireless network. Within each cell sector, theRF radiation pattern provides an air interface over which mobilestations may communicate with the cellular wireless network. In turn,the cellular wireless network may communicate with one or more othernetworks, such as the PSTN or a packet-switched network (e.g., theInternet). As such, when a mobile station is positioned within thecoverage area of the cellular wireless network (e.g., in given cellsector), the mobile station can communicate with entities on the othernetworks via the cellular wireless network.

The RF air interface of any given cell sector in the cellular wirelessnetwork is typically divided into a plurality of channels for carryingcommunications between the mobile stations and the cellular wirelessnetwork. For example, the RF air interface may include a plurality offorward-link channels, such as pilot channels, sync channels, pagingchannels, and forward-traffic channels, for carrying communications fromthe cellular wireless network to the mobile stations. As anotherexample, the RF air interface may include a plurality of reverse-linkchannels, such as access channels and reverse-traffic channels, forcarrying communications from the mobile stations to the cellularwireless network. However, the number of channels on the air interface,and thus the number of simultaneous communications the air interface cansupport, is limited by hardware and/or protocol constraints. As such,cellular wireless networks often try to conserve the limited supply ofchannels by assigning them on an as-needed basis.

One common way a cellular wireless network conserves channels is byemploying a paging process to locate a given mobile station beforeassigning a channel to the given mobile station. More particularly, whenthe cellular wireless network receives a request to set up acommunication with a given mobile station, the cellular wireless networkmay send a page message over a paging channel in each of a plurality ofcell sectors for receipt by the given mobile station. In this respect,the cellular wireless network is able to locate the given mobile stationusing the paging channel in each cell sector, without tying up trafficchannels.

Thereafter, if the given mobile station receives the page message in agiven cell sector, the given mobile station may indicate its location inthe given cell sector by sending a response back to the cellularwireless network over an access channel of the given cell sector. Inturn, the cellular wireless network may then assign the given mobilestation a traffic channel in the given cell sector by (i) reserving anavailable traffic channel for communication with the given mobilestation, and (ii) sending the given mobile station a channel assignmentmessage identifying the reserved traffic channel. Upon receipt of thechannel assignment message, the given mobile station may then acquirethe identified traffic channel, and communication over the trafficchannel may begin shortly thereafter.

Although the paging process described above enables the cellularwireless network to conserve its limited supply of channels whilelocating mobile stations, the exchange of multiple paging messages,including delay between theses messages, may introduce latency into thecommunication setup process. This latency may be undesirable, especiallyfor time sensitive applications such as Voice over IP (VoIP) andPush-to-Talk (PTT). As such, a cellular wireless network that reducesthe latency in the communication setup process would be desirable.

SUMMARY

The present invention is directed to an innovative method and system forsetting up a communication with a given mobile station served by a radioaccess network (RAN) that defines one or more coverage areas.

According to an example of the present invention, the given mobilestation may send, and the RAN may receive, an indication of location ofthe given mobile station (e.g., a GPS location reading). In thisrespect, the given mobile station may send the indication at varioustimes. For example, the given mobile station may send the indicationafter powering up. As another example, the given mobile station may sendthe indication periodically according to a schedule. As yet anotherexample, the given mobile station may send the indication in response toa change in location. Other examples are possible as well.

After receiving the indication of location, the RAN may use the locationof the given mobile station to identify one or more wireless coverageareas associated with the given mobile station. In this respect, the RANmay maintain information for its wireless coverage areas, and the RANmay then compare the location of the given mobile station to theinformation for its wireless coverage areas. Preferably, the RAN willidentify at least one wireless coverage area that encompasses thelocation of the given mobile station. The RAN may also store thelocation of the given mobile station for future reference.

The RAN may then receive a request to set up a communication with thegiven mobile station. In turn, the RAN may assign a channel for thecommunication to the given mobile station in each identified wirelesscoverage area, without first paging the given mobile station. Moreparticularly, for each identified wireless coverage area, the RAN may(i) reserve a channel for the communication and (ii) transmit a channelassignment message (e.g., a 1×RTT CAM or an EV-DO TCA) specifying thereserved channel for use by the given mobile station, without firstsending a page message for receipt by the given mobile station. Thechannel assignment message may contain identifying information for thechannel as well as an identifier of the intended recipient, which is thegiven mobile station.

If the given mobile station accepts assignment of a channel in a givenwireless coverage area, the given mobile station may send to the RAN,and the RAN may receive, an indication that the given mobile station hasaccepted the assignment of the channel in the given wireless coveragearea. In turn, the RAN may release assigned channels in other identifiedwireless coverage area. Further, if the given mobile station does notaccept an assigned channel in an identified wireless coverage areawithin a predetermined time period, the RAN may also release theassigned channel. Still further, if the RAN determines that the givenmobile station has not accepted the assignment of a channel in any ofthe one or more identified wireless coverage areas within apredetermined time period, the RAN may then page the given mobilestation.

In summary, in accordance with one aspect, an exemplary embodiment ofthe present invention may take the form of a method for setting up acommunication with a given mobile station served by a RAN that definesone or more coverage areas. The method may involve (a) receiving anindication of a location of the given mobile station, (b) using thelocation of the given mobile station to identify one or more wirelesscoverage areas associated with the given mobile station, (c) receiving arequest to set up a communication with the given mobile station, and (d)assigning a channel for the communication to the given mobile station ineach identified wireless coverage area without first paging the givenmobile station.

Additionally, the method may also involve (e) receiving from the givenmobile station an indication that the given mobile station has acceptedassignment of a channel in a given identified wireless coverage area,(f) releasing an assigned channel in a first identified wirelesscoverage area in response to receiving an indication that the givenmobile station has accepted assignment of a channel in a secondidentified wireless coverage area, (g) releasing an assigned channel ina given identified wireless coverage area after a predetermined timeperiod unless the given mobile station has accepted assignment of thechannel in the given identified wireless coverage area, and (h)determining that the given mobile station has not accepted theassignment of a channel in any of the one or more identified wirelesscoverage areas within a predetermined time period and responsivelypaging the given mobile station.

The indication of the location may be a GPS location reading from thegiven mobile station, which the given mobile station sends at varioustimes. Further, the function of using the location of the given mobilestation to identify one or more wireless coverage areas associated withthe given mobile station may include (i) maintaining information aboutthe one or more coverage areas of the radio access network, and (ii)comparing the location of the given mobile station to the informationabout the one or more coverage areas. Further yet, the identified one ormore coverage areas will preferably encompass the location of the givenmobile station.

The function of assigning a channel for the communication to the givenmobile station in each identified wireless coverage area without firstpaging the given mobile station may include, for each identifiedwireless coverage area, (i) reserving a channel for the communication,and (ii) transmitting a channel assignment message specifying thereserved channel for use by the given mobile station, without firstsending a page message for receipt by the given mobile station. Thechannel assignment message may be a 1×RTT CAM or an EV-DO TCA messagefor instance. Further, the channel assignment message may contain anidentifier of the given mobile station as well as identifyinginformation for the assigned channel (e.g., carrier frequency, PNoffset, Walsh code, and/or MAC identifier).

In another aspect, an exemplary embodiment of the invention may take theform of a RAN serving a given mobile station. The RAN may include (a) anantenna structure for communicating with mobile stations via an airinterface, (b) a communication interface for communicating with one ormore networks, (c) a processor, (d) data storage, and (e) programinstructions stored in the data storage and executable by the processorto carry out various functions as described herein.

These as well as other aspects and advantages will become apparent tothose of ordinary skill in the art by reading the following detaileddescription, with reference where appropriate to the accompanyingdrawings. Further, it should be understood that the embodimentsdescribed in this summary and elsewhere are intended to be examples onlyand do not necessarily limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of a telecommunications system inwhich an exemplary embodiment of the invention can be implemented;

FIG. 2 is a simplified block diagram of the telecommunications system ofFIG. 1 with a first exemplary radio access network for facilitating airinterface communications according to a CDMA 1×RTT protocol;

FIG. 3 is a simplified block diagram of the telecommunications system ofFIG. 1 with a second exemplary radio access network for facilitating airinterface communications according to a CDMA EV-DO protocol;

FIG. 4 is a flow chart depicting a method for setting up a communicationwith a given mobile station served by the radio access network of FIG.1, according to the exemplary embodiment of the present invention.

FIG. 5 is a simplified block diagram of an Access Node, showingfunctional components that can operate to carry out aspects of theexemplary embodiment.

DETAILED DESCRIPTION

Referring to the drawings, FIG. 1 is a simplified block diagram of atelecommunications system 10 in which an exemplary embodiment of theinvention can be implemented. As shown, the system 10 includes at itscore a radio access network (RAN) 12, which may function to provideconnectivity between one or more mobile stations 14 (e.g., a cell phone,PDA, or other wirelessly-equipped device), and one or more transportnetworks, such as a circuit-switched network 16 (e.g., the publicswitched telephone network (PSTN)) or a packet-switched network (e.g.,the Internet) 18.

It should be understood, however, that this and other arrangementsdescribed herein are set forth for purposes of example only. As such,those skilled in the art will appreciate that other arrangements andother elements (e.g., machines, interfaces, functions, orders offunctions, etc.) can be used instead, some elements may be added, andsome elements may be omitted altogether. Further, as in mosttelecommunications applications, those skilled in the art willappreciate that many of the elements described herein are functionalentities that may be implemented as discrete or distributed componentsor in conjunction with other components, and in any suitable combinationand location. Still further, various functions described herein as beingperformed by one or more entities may be carried out by hardware,firmware and/or software logic. For instance, various functions may becarried out by a processor executing a set of machine languageinstructions stored in memory.

As shown in FIG. 1, the RAN 12 may include an antenna structure 20.(Although FIG. 1 depicts the RAN 12 with one antenna structure 20, itshould be understood that the RAN 12 may include a plurality of antennastructures 20). The antenna structure 20 may transmit RF radiationpatterns at one or more carrier frequencies, and the RF radiationpatterns may then provide one or more air interfaces 22 through whichthe mobile stations 14 may communicate with the RAN 12. For example, theantenna structure 20 may transmit omni-directional RF radiation patternsthat provide a single air interface 22. Alternatively, the antennastructure 20 may transmit directional RF radiation patterns that providemultiple air interfaces 22.

Each of one or more air interfaces 22 of the antenna structure 20 maythen define a corresponding wireless coverage area of the antennastructure 20. For example, if the antenna structure 20 provides a singleair interface 22, then the antenna structure 20 may serve a singlewireless coverage area (e.g., a cell). In this respect, the airinterface 22 and corresponding wireless coverage area may becharacterized by the one or more carrier frequencies of the antennastructure 20. Alternatively, if the antenna structure 20 providesmultiple air interfaces 22, the antenna structure 20 may serve multiplewireless coverage areas (e.g., cell sectors). In this respect, each ofthe air interfaces 22 and corresponding wireless coverage areas may becharacterized by the one or more carrier frequencies of the antennastructure 20 and a pseudo-random number offset (PN offset) thatdistinguishes one wireless coverage area of the antenna structure 20from another.

The air interfaces 22 may carry communications between the RAN 12 andmobile stations 14 according to any of a variety of protocols. Forexample, the air interfaces 22 may carry communications compliant with aCode Division Multiple Access (CDMA) protocol, such as IS-95, 1×RTT(“Single Carrier Radio Transmission Technology”), or EV-DO (EvolutionData Optimized). As another example, the air interfaces 22 may carrycommunications compliant with a Time Division Multiple Access (TDMA) orGlobal System for Mobile Communication (GSM) protocol. Other examplesare possible as well.

Depending on the protocol employed, the air interfaces 22 may also bedivided into a plurality of channels for carrying different types ofcommunications between the mobile stations 14 and the RAN 12. Forexample, each air interface 22 may include a plurality of forward-linkchannels (e.g., control channels, forward-traffic channels, etc.) forcarrying forward-link communications from the RAN 12 to the mobilestations 14. As another example, each air interface 22 may include aplurality of reverse-link channels (e.g., access channels,reverse-traffic channels, etc.) for carrying reverse-link communicationsfrom the mobile stations 14 to the RAN 12.

As show in FIG. 1, the RAN 12 may also include channel elements 24,which may function to support communication over the air interfacechannels by performing various signal processing functions. For example,without limitation, the channel elements 24 may perform forward-linkencoding and modulation, data symbols addition, forward power gainadjustment, reverse-link demodulation, frame quality determination,and/or reverse power control. The RAN 12 may have one or more sets ofchannel elements 24, each corresponding to a different air interface 22and wireless coverage area of the RAN 12. Preferably, each channelelement 24 in a given set will then support a single air interfacechannel. As such, when a given mobile station 14 and the RAN 12 areengaged in communication over an air interface channel, the RAN 12 maydedicate a corresponding channel element 24 for that communication. Thechannel elements 24 may also provide an interface between the antennastructures 20 of the RAN 12 and other components of the RAN 12.

The RAN 12 may then provide connectivity to the circuit-switched network16, such as the PSTN, and the packet-switched network 18, such as theInternet. Accordingly, with this general arrangement, the RAN 12 mayfacilitate communications between two mobile stations 14 within the RAN's coverage areas, as well as between a given mobile station 14 andanother communication device coupled to the circuit-switched network 16or the packet-switched network 18.

Depending on the protocol used to carry communications between the RAN12 and the mobile stations 14, the RAN 12 may include various entitiesfor facilitating air interface communications with the mobile stations14. FIG. 2 is a simplified block diagram of the system 10 with a firstexemplary RAN 12 for facilitating air interface communications accordingto the CDMA 1×RTT protocol. As shown, the first exemplary RAN 12 mayinclude at least one base transceiver stations (BTS) 32, a base stationcontroller (BSC) 34, a mobile switching center (MSC) 36, and a packetdata serving node (PDSN) 38.

Each BTS 32 of the first exemplary RAN 12 may include, among othercomponents, at least one of the antenna structures 20 and one or moresets of channel elements 24. As such, each BTS 32 may provide one ormore air interfaces 22 for communication with the mobile stations 14.Each BTS 32, via the channel elements 24, may then couple to the BSC 34,which may function to communicate with each BTS 32 and control aspectsof the BTS 32 as well as aspects of the air interface communication withthe mobile stations 14. The BTS 32 and the BSC 34 together may also bereferred to as a “Base Station.” The BSC 34 may then couple to the MSC36, which may provide connectivity with the circuit-switched network 16and/or a signaling network (not shown). Further, the BSC 34 may coupleto the PDSN 38, which may provide connectivity with the packet-switchednetwork 18. The connections between the entities of the exemplary RAN12, other than the air interfaces 22, may include physical cables, suchas T1 trunk lines or E1 trunk lines, and/or wireless links, such asmicrowave links or satellite channels.

According to the 1×RTT protocol, each air interface 22 and correspondingwireless coverage area of the first exemplary RAN 12 may becharacterized by the one or more carrier frequencies of the antennastructure 20 and a PN offset that distinguishes one wireless coveragearea from another. Further, according to the 1×RTT protocol, each airinterface 22 may be divided into a plurality of channels that aredistinguished by Walsh codes, which are digital modulation codes thatdistinguish individual signals on the one or more carrier frequenciesbeing transmitted. These Walsh codes may be reused in adjacent wirelesscoverage areas because channel separation is provided by a different PNoffset. As such, the given mobile station 14 and the RAN 12 may engagein 1×RTT communications over air interface channels characterized by oneor more carrier frequencies, a PN offset, and a Walsh code.

Typically, when setting up a communication with a given mobile station14 according to the 1×RTT protocol, the BSC 34 may first receive aPaging Request (e.g., from the MSC 36). In turn, the BSC 34 may directthe BTS 32 to send a Page Message over each air interface 22 for receiptby the given mobile station 14, in order to locate the given mobilestation 14. If the given mobile station 14 is located in one of thewireless coverage areas of the first exemplary RAN 12 and receives thePage Message over a given air interface 22, the given mobile station 14may then send a Page Response Message back to the first exemplary RAN 12over the given air interface 22. Thereafter, the BSC 34 may direct theBTS 32 to send an Acknowledgement (ACK) message to the given mobilestation 14, and the BSC may then direct the BTS 32 to send a ChannelAssignment Message (CAM) to the given mobile station 14 that containsidentifying information for a traffic channel. In this respect, the BSC34 may also exchange signaling messages with the MSC 36 before directingthe BTS 32 to send the CAM.

FIG. 3 is a simplified block diagram of the system 10 with a secondexemplary RAN 12 for facilitating air interface communications accordingto the CDMA EV-DO protocol. As shown, the second exemplary RAN 12 ofFIG. 3 may include at least one Node-Bs 42, a radio network controller(RNC) 44, a media gateway (MGW) 46, and a PSDN 48.

Each Node-Bs 42 of the second exemplary RAN 12 may include, among othercomponents, at least one of the antenna structures 20 and one or moresets of channel elements 24. As such, each Node-Bs 42 may provide one ormore air interfaces 22 for communication with the mobile stations 14.Each Node-Bs 42 may then couple to the RNC 44, which may function tocommunicate with each Node-Bs 42 and control aspects of the Node-Bs 42as well as aspects of the air interface communication with the mobilestations 14. The Node-Bs 42 and the RNC 44 together may be referred toas an “Access Node.” The RNC 44 may then couple to the MGW 46, which mayprovide connectivity with the circuit-switched network 16. Further, theRNC 44 may couple to the PDSN 38, which may provide connectivity withthe packet-switched network 18. In this respect, the RNC 44 mayadditionally include a packet control function (“PCF”) for controllingpacket-data communications. The connections between the entities of theexemplary RAN 12, other than the air interfaces 22, may include physicalcables, such as T1 trunk lines or E1 trunk lines, and/or wireless links,such as microwave links or satellite channels.

According to the EV-DO protocol, each air interface 22 and correspondingwireless coverage area of the second exemplary RAN 12 may becharacterized by the one or more carrier frequencies of the antennastructure 20 and a PN offset that distinguishes one wireless coveragearea from another. Further, according to the EV-DO protocol, theforward-link of each air interface 22 may be divided into time slotsthat are time division multiplexed to carry various channels, includinga pilot channel (which carries an indication of PN offset), a MediumAccess Control (MAC) channel, and a data channel that may include aforward traffic channel and a “control” channel. The data channels onthe forward link are distinguished by MAC identifiers, which identifythe time slots of the forward link which correspond to a given datachannel. Further yet, according to the EV-DO protocol, the reverse-linkof each air interface 22 may be divided into a plurality of channelsthat are distinguished by Walsh codes. As such, the given mobile station14 and the RAN 12 may engage in EV-DO communications over air interfacechannels characterized by one or more carrier frequencies, a PN offset,and either a MAC identifier or a Walsh code.

Typically, when setting up a communication with a given mobile station14 according to the EV-DO protocol, the RNC 44 may first direct theNode-Bs 42 to page the given mobile station 14. In turn, the Node-Bs 42may acknowledge the RNC's paging request, and the Node-Bs may then senda Page Message (e.g., CCSynSS:Page message) over each air interface 22for receipt by the given mobile station 14, in order to locate the givenmobile station 14. If the given mobile station 14 is located in one ofthe wireless coverage areas of the second exemplary RAN 12 and receivesthe Page Message over a given air interface 22, the given mobile station14 may then send a Connection Request message (e.g.,AC:ConnectionRequest message) back to the second exemplary RAN 12 overthe given air interface 22. Thereafter, the RNC 44 may perform variousactions to facilitate communication with the given mobile station 14,such as determining whether the given mobile station is authorized toengage in packet-data communications and setting up a communication pathwith the PSDN 48. Once these actions are complete, the RNC 44 may thendirect the Node-Bs 42 to send a Traffic Channel Assignment (TCA) messageto the given mobile station 14 that contains identifying information fora traffic channel.

FIG. 4 is a flow chart depicting a method for setting up a communicationwith a given mobile station 14 served by the RAN 12 that defines one ormore coverage areas, according to the exemplary embodiment of thepresent invention. The RAN 12 may be either of the exemplary RANsdescribed above, or some other RAN.

The method may begin at step 52 when the RAN 12 receives an indicationof a location of the given mobile station 14. Preferably, the RAN 12will receive the indication of location from the given mobile station 14via an air interface 22. The given mobile station 14 may sendindications of its location to the RAN 12, and the RAN 12 may thenreceive the indications of location, at various times.

For example, the given mobile station 14 may send indications of itslocation to the RAN 12 after powering up. As another example, the givenmobile station 14 may send indications of its location to the RAN 12periodically according to a schedule, such as every 30 minutes. As yetanother example, the given mobile station 14 may send indications of itslocation to the RAN 12 in response to a change in location. In thisrespect, the given mobile station 14 may send an indication of itslocation when the given mobile station 14 has moved more than apredetermined distance since sending the last indication of location.Additionally or alternatively, the given mobile station 14 may send anindication of its location when the given mobile station 14 has movedinto a different wireless coverage area. As a further example, the givenmobile station 14 may send indications of its location to the RAN 12 inresponse to a request from the RAN 12. Ideally, in determining when tosend the indications of location, the given mobile station 14 willbalance the benefits of keeping the RAN 12 updated of its location withthe drawbacks of overloading the network with location update messages.As such, the given mobile station 14 may additionally limit the numberof location indications it sends to the RAN 12 in any given time period(e.g., only 1 message every 30 minutes).

The indication of location of the given mobile station may take avariety of forms. In one example, the indication of the location mayconsist of a GPS location reading, which the given mobile station 14 maydetermine via a GPS receiver. Alternatively, the indication of thelocation may consist of information about signals the given mobilestation 14 is receiving from the RAN 12, such as detected strength ofpilot signals of the one or more air interfaces 22, which the RAN 12 mayuse to determine the given mobile station's location. Other examples arepossible as well. In any case, the given mobile station 14 may send theindication of location to the RAN 12 using different communicationforms, including packet-data communication.

At step 54, the RAN 12 may then use the location of the given mobilestation 14 to identify one or more wireless coverage areas associatedwith the given mobile station 14. The RAN 12 may perform this functionin response to (i) receiving the indication of the location of the givenmobile station, (ii) receiving a request to set up a communication withthe given mobile station 14 (as described at step 56), and/or (iii) someother triggering event.

To assist in identifying the wireless coverage areas associated with thegiven mobile station 14, the RAN 12 may maintain information for thewireless coverage areas that it serves. As an example, for each of itswireless coverage areas, the RAN 12 may maintain one or more identifiersof the wireless coverage area (e.g., a carrier frequency and/or PNoffset) along with boundary information (e.g., coordinates) for thewireless coverage area. The RAN 12 may then compare the location of thegiven mobile station 14 to the maintained information for its wirelesscoverage areas, to identify which wireless coverage areas may beassociated with the given mobile station 14. Preferably, the RAN 12 willidentify at least one wireless coverage area that encompasses thelocation of the given mobile station 14, which may be referred to as a“reference sector.” Further, the RAN 12 may identify other wirelesscoverage areas that do not encompass the location of the given mobilestation 14, but are near the reference sector. For example, the RAN 12may identify wireless coverage areas that are adjacent to the referencesector. Ideally, the identified wireless coverage areas associated withthe given mobile station 14 will consist of the wireless coverage areasin which the given mobile station 14 may be located.

After receiving the indication of the location of the given mobilestation 14, the RAN 12 may also store the location of the given mobilestation 14. In this respect, the RAN 12 may maintain historical locationdata for various mobile stations 14, including the given mobile station14. The RAN 12 may then use this historical location data to moreaccurately identify the wireless coverage areas associated with thegiven mobile station 14. For example, the RAN 12 may use the historicaldata to track past movement of the given mobile station 14 and predictfuture locations of the given mobile station 14 based on past movement,which may then enable the RAN 12 to identify wireless coverage areasthat encompass and/or are near the predicted future locations.

At step 56, the RAN 12 may receive a request to set up a communicationwith the given mobile station 14. The requested communication may be anytype of communication, including a phone call, a packet data-session,and/or a short message service (SMS) session. Further, the RAN 12 mayreceive the request from one of various system entities. For example,the RAN 12 may receive the request via the circuit-switched network 16from a landline telephone or some other device coupled to thecircuit-switched network 16. As another example, the RAN 12 may receivethe request via the packet-switched network 18 from a VoIP telephone orsome other device coupled to the packet-switched network 18. Many otherexamples are possible as well.

At step 58, after receiving the communication request, the RAN 12 mayassign a channel for the communication to the given mobile station 14 ineach identified wireless coverage area, without first paging the givenmobile station 14. More particularly, for each identified wirelesscoverage area, the RAN 12 may (i) reserve a channel for thecommunication and (ii) transmit a channel assignment message specifyingthe reserved channel for use by the given mobile station, without firstsending a page message for receipt by the given mobile station.

The RAN 12 may reserve the channel for the communication by reservingresources corresponding to the channel. For example, to reserve a 1×RTTchannel in a given wireless coverage area, the RAN 12 may reserve aWalsh code and a channel element 24. As another example, to reserve anEV-DO channel in a given wireless coverage area, the RAN 12 may reservea MAC identifier. Other examples are possible as well.

The channel assignment message will preferably contain identifyinginformation for the channel, which the given mobile station 14 may useto acquire the channel. For example, if the channel assignment messageis a 1×RTT channel assignment message (CAM), the 1×RTT CAM may containone or more carrier frequencies, a PN offset, and/or a Walsh code. Asanother example, if the channel assignment message is an EV-DO trafficchannel assignment (TCA) message, the EV-DO TCA may contain one or morecarrier frequencies, a PN offset, and a MAC identifier. Other examplesare possible as well.

The channel assignment message may also contain an identifier of itsintended recipient, which may be the given mobile station 14. Theidentifier may be, for example, a mobile identification number (MIN), aninternational mobile subscriber identity (IMSI), a unicast accessterminal identifier (UATI), or some other identifier for a mobilestation 14. The given mobile station 14 may then use the identifier in areceived channel assignment message to determine whether the givenmobile station 14 is the intended recipient. In this respect, the givenmobile station 14 may accept the channel assignment message, and thechannel being assigned, if the identifier in the channel assignmentmessage matches an identifier of the given mobile station 14.

In addition to assigning a channel for the communication to the givenmobile station 14 in each identified wireless coverage area withoutfirst paging the given mobile station 14, the RAN 12 may also page thegiven mobile station 14 in all other wireless coverage areas of the RAN12. In this respect, the RAN 12 may still be able to locate the givenmobile station 14 even if the given mobile station 14 is not locatedwithin an identified wireless coverage.

If the given mobile station 14 is located in a given wireless coveragearea that is included in the one or more identified wireless coverageareas, then the given mobile station 14 may accept assignment of thechannel from the RAN 12 in the given wireless coverage area. In turn,the given mobile station 14 may send to the RAN 12, and the RAN 12 mayreceive, an indication that the given mobile station 14 has accepted theassignment of the channel in the given wireless coverage area. Forexample, in 1×RTT compliant communications, the given mobile station 14may send a Preamble message and/or an ACK message to the RAN 12. Asanother example, in EV-DO compliant communications, the given mobilestation 14 may send a Traffic Channel Complete (TCC) message. Otherexamples are possible as well.

During the channel assignment at step 58, the RAN 12 may also assignchannels to the given mobile station 14 in identified wireless coverageareas where the given mobile station 14 is not located. For example, thegiven mobile station 14 may be located in a first sector, but the RAN 12may assign channels to the given mobile station 14 in both the firstsector and a second sector that is adjacent to the first sector, sincethe RAN 12 identified both the first and second sectors as being sectorsin which the given mobile station 14 may be operating. In this respect,the given mobile station 14 may not be available to accept theassignment of channels in various identified wireless coverage areas ofthe RAN 12. As such, the RAN 12 may release an assigned channel in agiven identified wireless coverage area after a predetermined timeperiod (e.g., 100 ms) unless the given mobile station 14 has acceptedassignment of the channel in that given wireless coverage area.Alternatively, the RAN 12 may release an assigned channel in a firstidentified wireless coverage area if the RAN 12 receives an indicationthat the given mobile station 14 has accepted assignment of a channel ina second identified wireless coverage area. In either case, by releasingthe unused channels, the RAN 12 may later assign the channels to othermobile stations 14 that are located in these wireless coverage areas.

After the channel assignment at step 58, the RAN 12 may also determinethat the given mobile station 14 has not accepted the assignment of achannel in any of the one or more identified wireless coverage areaswithin a predetermined time period (e.g., 100 ms). For example, the RAN12 may determine that it has not received an indication that the givenmobile station 14 accepted assignment of a channel in any of theidentified wireless coverage areas within a predetermined time period.In response to this determination, the RAN 12 may then page the givenmobile station 14, such as by sending a page message for receipt by thegiven mobile station 14. Preferably, the predetermined time period formaking this determination will be substantially similar to thepredetermined time period for releasing the channels, as describedabove.

Advantageously, the method described above may reduce the number ofmessages exchanged when setting up a communication the given mobilestation 14 served by the RAN 12. More particularly, the present methodmay eliminate any paging messages exchanged between the given mobilestation 14 and the RAN 12, and the present method may also eliminatecertain signaling messages exchanged between entities of the RAN 12. Inturn, this reduction of messages (and the delay between the messages)may shorten the time for setting up the communication with the givenmobile station 14, which is desirable for certain customers andapplications (e.g., VoIP, PTT, etc.). Further, the reduction of messagesduring communication setup may also reduce the paging load of the RAN12.

The functionality of the present invention may be implemented in one ormore entities of the RAN 12. For example, the Access Node describedabove, which includes the Node-Bs 42 and the RNC 44, may carry outfunctions of the present invention. Accordingly, FIG. 5 is a simplifiedblock diagram of an Access Node, showing functional components that canoperate to carry out aspects of the present invention. As shown in FIG.5, the exemplary Access Node 70 includes, without limitation, an antennastructure 72, a communication interface 74, a processor 76, and datastorage 78, all linked together via a system bus, network, or otherconnection mechanism 80. The exemplary Access Node 70 may also includeother components, such as a PCF (not shown).

Referring to FIG. 5, the antenna structure 72 of the Access Node 70 maybe substantially similar to the antenna structure 20 described withreference to FIG. 1. As such, the antenna structure 72 may provide oneor more air interfaces 22 though which the mobile stations 14 maycommunicate with the Access Node 70. The antenna structure 72 may bearranged in various ways. For example, the antenna structure 72 mayinclude one or more antennas. In one respect, the one or more antennasmay include one or more omni-directional antennas and/or one or moredirectional (e.g., sectored) antennas. In another respect, the one ormore antennas may include one or more antennas for receiving RF signalsand one or more antennas for transmitting RF signals away from theantenna structure 72. The RF signals transmitted away from the antennastructure 72 may then provide the one or more air interfaces 22, each ofwhich defines a corresponding wireless coverage area.

The communication interface 74 preferably functions to communicativelycouple the Access Node 70 to other networks, such as thecircuit-switched network 16 via the MGW 46 and the packet-switchednetwork via the PSDN 48. As such, the communication interface 74 maytake the form of an Ethernet network interface card, a chipset andantenna adapted to facilitate wireless communication according a desiredprotocol, and/or any other form that provides for wireless and/or wiredcommunication with the other networks of the system 10. The Access Node70 may also include multiple communication interfaces 74, such as onethrough which the Access Node 70 sends communication, and one throughwhich the Access Node 70 receives communication.

The processor 76 may comprise one or more general purposemicroprocessors and/or dedicated signal processors. (The term“processor” encompasses either a single processor or multiple processorsthat could work in combination.) Data storage 78, in turn, may comprisememory and/or other storage components, such as optical, magnetic,organic or other memory or disc storage, which can be volatile and/ornon-volatile, internal and/or external, and integrated in whole or inpart with the processor 76. Data storage 78 preferably contains or isarranged to contain (i) program data 82 and (ii) program logic 84.Although these components are described herein as separate data storageelements, the elements could just as well be physically integratedtogether or distributed in various other ways. In a preferred example,the program data 82 would be maintained in data storage 78 separate fromthe program logic 74, for easy updating and reference by the programlogic 74.

Program data 82 may contain information about the wireless coverageareas of the Access Node 70. For example, program data 82 may containone or more identifiers of the wireless coverage areas, such as the oneor more carrier frequencies and/or the PN offset characterizing thewireless coverage area. As another example, program data 82 may containdefining information for each of the wireless coverage areas, such asboundary information in the form of coordinates. Program data 82 maycontain other information about the wireless coverage areas as well.

Program data 82 may also contain information about the location of themobile stations 14. For example, program data 82 may contain anidentifier for each mobile station 14 (e.g., an MIN, IMSI, and/or UATI),and program data 82 may then contain prior and/or current location datacorresponding to the identifiers of the mobile stations 14. In thisrespect, the Access Node 70 may use the location data to more accuratelyidentify associated wireless coverage areas for the mobile stations 14.

Program logic 84 preferably comprises machine language instructions thatmay be executed or interpreted by processor 76 to carry out functionsaccording to examples of the present invention, including the functionsdescribed with reference to FIG. 4. It should be understood, however,that the program logic 74 and its associated functions are describedherein by way of example only. As such, those skilled in the art willappreciate that other program logic and/or functions may be usedinstead, some program logic and/or functions may be added, and someprogram logic and/or functions may be omitted altogether. Further, thevarious functions described herein can be embodied in software,hardware, and/or firmware.

For example, the program logic 74 may be executable by the processor 76to (i) receive an indication of a location of the given mobile station14 via the antenna structure 72, (ii) use the location of the givenmobile station 14 to identify one or more wireless coverage areasassociated with the given mobile station 14 (e.g., by referencingprogram data 82), (iii) receive a request to set up a communication withthe given mobile station 14 via the communication interface 74, and (iv)assign a channel for the communication to the given mobile station 14 ineach identified wireless coverage area via the antenna structure 72,without first paging the given mobile station 14.

Further, after assigning channels to the given mobile station 14, theprogram logic 74 may be executable by the processor 76 to (i) receive anindication that the given mobile station 14 has accepted the assignmentof a channel in a given wireless coverage area, (ii) release an assignedchannel in a given identified wireless coverage area after apredetermined time period unless the given mobile station 14 hasaccepted assignment of the channel, (iii) release an assigned channel ina first identified wireless coverage area in response to receiving anindication that the given mobile station 14 has accepted assignment of achannel in a second identified wireless coverage area, and (iv) page thegiven mobile station 14 in response to a determination that the givenmobile station 14 has not accepted the assignment of a channel in any ofthe one or more identified wireless coverage areas within apredetermined time period.

Exemplary embodiments of the present invention have been describedabove. Those skilled in the art will understand, however, that changesand modifications may be made to the embodiments described withoutdeparting from the true scope and spirit of the present invention, whichis defined by the claims.

1. A method comprising: in a radio access network, receiving a requestto set up a communication with a given mobile station; in response toreceiving the request, and without first sending a message to locate thegiven mobile station, (a) reserving a channel for the communication withthe given mobile station in each of two or more wireless coverage areasof the radio access network and (b) transmitting, in each of the two ormore wireless coverage areas, a message identifying the channel reservedfor the communication in the respective wireless coverage area;receiving an indication that the given mobile station has accepted thechannel reserved for the communication in a given one of the two or morewireless coverage areas; and in response to receiving the indication,releasing the channel reserved for the communication in every other ofthe two or more wireless coverage areas.
 2. The method of claim 1,further comprising: before receiving the request to set up thecommunication with the given mobile station, receiving an indication ofa location of the given mobile station.
 3. The method of claim 2,wherein the indication of the location of the given mobile stationcomprises one or more of: a GPS location reading for the given mobilestation; and information about signals the given mobile station hasreceived from the radio access network.
 4. The method of claim 2,wherein receiving the indication of the location of the given mobilestation comprises one or more of: receiving the indication of thelocation periodically according to a schedule; and receiving theindication of the location in response to a change in location by thegiven mobile station.
 5. The method of claim 2, further comprising:storing the indication of the location of the given mobile station. 6.The method of claim 2, wherein the two or more wireless coverage areascomprise two or more coverage areas identified based on the indicationof the location of the given mobile station.
 7. The method of claim 2,wherein at least one of the two or more wireless coverage areasencompasses the location of the given mobile station.
 8. The method ofclaim 1, wherein each of the two or more wireless coverage areascomprises a cell sector.
 9. The method of claim 1, wherein each messageidentifying a channel reserved for the communication in a respectivewireless coverage area comprises a channel assignment message.
 10. Themethod of claim 1, wherein each message identifying a channel reservedfor the communication in a respective wireless coverage area contains anidentifier of the given mobile station.
 11. The method of claim 10,wherein the identifier of the given mobile station comprises one or moreof: a mobile identification number; an international mobile subscriberidentity; and a unicast access terminal identifier.
 12. The method ofclaim 1, wherein each message identifying a channel reserved for thecommunication in a respective wireless coverage area contains one ormore of a carrier frequency, a pseudorandom number offset, a Walsh code,and a MAC identifier.
 13. The method of claim 1, wherein the indicationthat the given mobile station has accepted the channel reserved for thecommunication in the given one of the two or more wireless coverageareas comprises one or more of: a preamble message; an ACK message; anda Traffic Channel Complete message.
 14. A radio access networkcomprising: one or more antenna structures for communicating with mobilestations located in a plurality of wireless coverage areas; a processor,data storage; and program instructions stored in the data storage andexecutable by the processor to carry out functions including: receivinga request to set up a communication with a given mobile station; inresponse to receiving the request, and without first sending a messageto locate the given mobile station, (a) reserving a channel for thecommunication with the given mobile station in each of two or morewireless coverage areas and (b) transmitting, in each of the two or morewireless coverage areas, a message identifying the channel reserved forthe communication in the respective wireless coverage area; receiving anindication that the given mobile station has accepted the channelreserved for the communication in a given one of the two or morewireless coverage areas; and in response to receiving the indication,releasing the channel reserved for the communication in every other ofthe two or more wireless coverage areas.
 15. The radio access network ofclaim 14, wherein the functions further include: before receiving therequest to set up the communication with the given mobile station,receiving an indication of a location of the given mobile station. 16.The method of claim 15, wherein the indication of the location of thegiven mobile station comprises one or more of: a GPS location readingfor the given mobile station; and information about signals the givenmobile station has received from the radio access network.
 17. The radioaccess network of claim 15, wherein the two or more wireless coverageareas comprise two or more coverage areas identified based on theindication of the location of the given mobile station.
 18. The radioaccess network of claim 14, wherein each message identifying a channelreserved for the communication in a respective wireless coverage areacomprises a channel assignment message.
 19. The radio access network ofclaim 14, wherein the indication that the given mobile station hasaccepted a channel reserved for the communication in a given one of thetwo or more wireless coverage areas comprises one or more of: a preamblemessage; an ACK message; and a Traffic Channel Complete message.
 20. Theradio access network of claim 14, further comprising channel elements,and wherein reserving a channel for the communication with the givenmobile station in each of two or more wireless coverage areas comprisesreserving a channel element for the communication with the given mobilestation in each of two or more wireless coverage areas.